A. All storm sewer systems shall be designed for a ten-year frequency storm. The minimum pipe diameter shall be twelve inches. The system shall have a free outlet. The minimum diameter for road ditch culverts shall be fifteen inches.
B. The maximum distance for overland flow of stormwater runoff shall be three hundred feet.
C. All manholes and catchbasins shall be constructed in accordance with the attached standard details which are located at the end of this title. (Standard Drawings No. 10 & 11)
D. The maximum distance between manholes shall be as follows: The sewer shall be constructed in a straight line between manholes.
12" diameter - 300 feet
12"-24" diameter - 350 feet
over 24" diameter - 500 feet
E. Trench backfill requirements shall conform to the applicable portions of the Standard Specification for Road and Bridge Construction, State of Illinois, Department of Transportation.
F. All design calculations must be submitted to the city engineer for approval.
G. The type of sewer pipe shall be:
1. Concrete and/or reinforced concrete pipe;
2. Bituminous coated corrugated steel culvert pipe;
3. Bituminous coated corrugated aluminum alloy culvert pipe.
H. The strength requirements of the sewer pipe shall conform to the requirements of the Standard Specification for Road and Bridge Construction, Department of Transportation. The appropriate tests must be submitted to the city engineer to verify the strength of the pipe used.
I. Surface drainage will be permitted for stormwater where cost estimates show storm sewers are not economically feasible and topographic conditions indicate there will be no difficulty from this method of disposal of stormwaters.
(Ord. 81-10 § 9.1 (A), 1980).